CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Operating activities
Net loss before noncontrolling interest	$ (29,352)	$ (40,831)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation expense	6,369	5,746
Depreciation and amortization	593	717
Loss on debt extinguishment	0	163
Loss on sublease	0	1,584
Gain on dissolution of a foreign entity	(4,288)	0
Noncash interest expense	525	163
Noncash rent benefit	(1,424)	(648)
Unrealized foreign exchange loss	362	0
Other	432	(18)
Changes in operating assets and liabilities:
Accounts receivable	4	402
Receivables from license and development services arrangements	(12,389)	6,579
Inventory	0	1,120
Prepaid expenses and other current assets	253	326
Other assets	(420)	63
Accounts payable	1,869	(4,730)
Accrued expenses	(946)	(11,096)
Deferred revenue	(1,407)	790
Other liabilities	(5)	374
Net cash used in operating activities	(39,824)	(39,296)
Investing activities
Purchases of property and equipment	(33)	(49)
Purchases of short-term investments	(42,067)	0
Proceeds from maturities of short-term investments	11,610	0
Proceeds from sale of available-for-sale securities	0	11
Net cash used in investing activities	(30,490)	(38)
Financing activities
Proceeds from common stock offering, net of issuance costs	64,170	0
Cash paid for at-the-market equity offering issuance costs	(168)	0
Proceeds from issuance of preferred stock, net of issuance costs	0	42,669
Payments of issuance costs from Silicon Valley Bank debt, net of issuance costs	(100)
Proceeds from Silicon Valley Bank debt, net of issuance costs		15,971
Repayment of debt	(444)	(19,548)
Payment of tax withholding obligations related to stock compensation	(21)	(87)
Proceeds from stock option exercises	46	0
Proceeds from ESPP stock issuance	8	10
Cash paid for repurchase of fractional shares	0	(36)
Net cash provided by financing activities	63,491	38,979
Effect of exchange rate changes on cash and cash equivalents	44	(429)
Net decrease in cash, cash equivalents and restricted cash	(6,779)	(784)
Cash, cash equivalents and restricted cash at beginning of year	43,218	44,002
Cash, cash equivalents and restricted cash at end of year	36,439	43,218
Supplemental disclosure of cash flow information
Cash paid during the period for interest	1,197	1,970
Supplemental disclosure of noncash financing and investing activities
Exchange of common stock and preferred stock for preferred stock	24,080	0
Conversion of preferred stock to common stock	$ 0	$ 41,579